This invention relates to an apparatus for detecting the abnormality and limit of use of a plain bearing which supports a rotary shaft.
The method disclosed in U.S. Pat. No. 4460893 is known as one of the methods of detecting the abnormality of bearings. This U.S. Patent shows the detecting by a thermocouple of a temperature rise occurring when an abnormal metallic contact takes place between a rotary shaft and a bearing.
However, in this method, a complicated control circuit is required to detect an abnormal condition of a bearing. Moreover, when a bearing wears so greatly that the abrasion loss of the bearing has exceeded a limit level, detecting this abnormality is impossible.